Multituberculata

{{Short description|Extinct order of mammals}} {{Automatic taxobox | name = Multituberculates | fossil_range = Middle Jurassic-Late Eocene {{Fossil range|168|34}} | image = Catopsbaatar catopsaloides.jpg | image_caption = Skeleton of ''Catopsbaatar'' | taxon = Multituberculata | authority = Cope, 1884 | subdivision_ranks = Suborders | subdivision = * †Plagiaulacida (paraphyletic) * †Cimolodonta }}

'''Multituberculata''' (commonly known as '''multituberculates''', named for the multiple tubercles of their teeth) is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years.{{citation needed|date=May 2024}} They first appeared in the Middle Jurassic, and reached a peak diversity during the Late Cretaceous and Paleocene. They declined from the mid-Paleocene onwards, finally going extinct in the late Eocene.<ref name="Krause 1986"/> They are the most diverse order of Mesozoic mammals with more than 200 species known, ranging from mouse-sized to beaver-sized. These species occupied a diversity of ecological niches, ranging from burrow-dwelling to squirrel-like arborealism to jerboa-like hoppers.<ref name="Weil">{{cite web |url=http://www.ucmp.berkeley.edu/mammal/multis/multis.html |title=Introduction to Multituberculates: The 'Lost Tribe' of Mammals |first=Anne |last=Weil |publisher=UCMP |location=Berkeley |date=June 1997 }}</ref><ref>{{cite journal | last1 = Chen | first1 = Meng | last2 = Philip Wilson | first2 = Gregory | year = 2015| title = A multivariate approach to infer locomotor modes in Mesozoic mammals | journal = Paleobiology | volume = 41| issue = 2| pages = 280–312| doi = 10.1017/pab.2014.14 | bibcode = 2015Pbio...41..280C | s2cid = 86087687 }}</ref> Multituberculates are usually placed as crown mammals outside either of the two main groups of living mammals, Theria — placentals and marsupials — and Monotremata,<ref name="Agusti-3">Agustí-Antón 2002, pp 3-4</ref> but usually as closer to Theria than to monotremes.<ref>Benton, Michael J. ''Vertebrate Palaeontology'' (2004), [https://books.google.com/books?id=P1LkOL1CijEC&pg=PA300 p. 300]</ref><ref>Carrano, Matthew T., and Richard W. Blob, Timothy J. Gaudin, and John R. Wible (2006). ''Amniote Paleobiology: Perspectives on the Evolution of Mammals, Birds, and Reptiles'', [https://books.google.com/books?id=4uNMCqSRQ9gC&pg=PA358 p. 358].</ref> They are considered to be closely related to Euharamiyida and Gondwanatheria as part of Allotheria.

== Description == [[File:Taeniolabis NT small.jpg|thumb|left|Restoration of ''Taeniolabis'', the largest multituberculate at approximately {{convert|22|kg|abbr=on}}.]] The multituberculates had a cranial and dental anatomy superficially similar to rodents such as mice and rats, with cheek-teeth separated from the chisel-like front teeth by a wide tooth-less gap (the diasteme). Each cheek-tooth displayed several rows of small cusps (or tubercles, hence the name) that operated against similar rows in the teeth of the jaw; the exact homology of these cusps to therian ones is still a matter of debate.{{citation needed|date=June 2020}} Unlike rodents, which have ever-growing teeth, multituberculates underwent dental replacement patterns typical of most mammals (though in at least some species the lower incisors continued to erupt long after the root's closure).<ref name="p. 299">Kielan-Jaworowska, Zofia, Richard L. Cifelli, and Zhe-Xi Luo (2005). ''Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure '', [https://books.google.com/books?id=qJGcX3X0EaMC&pg=PA299 p. 299]</ref> Multituberculates are notable for the presence of a massive fourth lower premolar, the plagiaulacoid; other mammals, like Plesiadapiformes and diprotodontian marsupials, also have similar premolars in both upper and lower jaws, but in multituberculates this tooth is massive and the upper premolars are not modified this way. In basal multituberculates all three lower premolars were plagiaulacoids, increasing in size posteriorly, but in Cimolodonta only the fourth lower premolar remained, with the third one remaining only as a vestigial peg-like tooth,<ref name="p. 299"/> and in several taxa like taeniolabidoideans, the plagiaulacoid disappeared entirely or was reconverted into a molariform tooth.<ref>Gurovich 2005 p. 334{{full citation needed|date=September 2021}}</ref><ref name="Gurovich & Beck 2009">{{cite journal |last1=Gurovich |first1=Yamila |last2=Beck |first2=Robin |date=March 2009 |title=The Phylogenetic Affinities of the Enigmatic Mammalian Clade Gondwanatheria |journal=Journal of Mammalian Evolution |volume=16 |issue=1 |pages=25–49 |doi=10.1007/s10914-008-9097-3 |s2cid=42799370}}</ref><ref>Rougier et al. 2009 p.233{{full citation needed|date=September 2021}}</ref>

[[File:Ptilodus skull BW.jpg|thumb|Skull of ''Ptilodus''. Notice the massive blade-like lower premolar.]]

Unlike rodents and similar therians, multituberculates had a palinal jaw stroke (front-to-back), instead of a propalinal (back-to-front) or transverse (side-to-side) one; as a consequence, their jaw musculature and cusp orientation is radically different.<ref name="Agusti-3" /><ref name="p. 299"/> Palinal jaw strokes are almost entirely absent in modern mammals (with the possible exception of the dugong<ref>{{cite journal |last1=Lanyon |first1=J. M. |last2=Sanson |first2=G. D. |title=Degenerate dentition of the dugong (Dugong dugon), or why a grazer does not need teeth: morphology, occlusion and wear of mouthparts |journal=Journal of Zoology |date=February 2006 |volume=268 |issue=2 |pages=133–152 |doi=10.1111/j.1469-7998.2005.00004.x }}</ref>), but are also present in haramiyidans, argyrolagoideans and tritylodontids, the former historically united with multituberculates on that basis. Multituberculate mastication is thought to have operated in a two stroke cycle: first, food held in place by the last upper premolar was sliced by the bladelike lower pre-molars as the dentary moved orthally (upward). Then the lower jaw moved palinally, grinding the food between the molar cusp rows.<ref name="Agusti-3" /><ref name="p. 299"/> [[File:American Jurassic Mammals plate VII.jpg|thumb|Lower jaws and teeth of allodontid multituberculates]]

The structure of the pelvis in the Multituberculata suggests that they gave birth to tiny helpless, underdeveloped young, similar to modern marsupials, such as kangaroos.<ref name="Weil" /><ref name="p. 299"/> However, a 2022 study reveals that they might actually have had long gestation periods like placentals.<ref>{{cite web | url=https://news.umich.edu/new-study-challenges-old-views-on-whats-primitive-in-mammalian-reproduction/ | title=New study challenges old views on what's 'primitive' in mammalian reproduction | date=25 July 2022 }}</ref> However, in 2024, all Allotheria (including multituberculates) fell outside the crown group of Mammalia, implying that cimolodonts developed placental-like gestation (and viviparity in general) independently, rather than multituberculates and therians having a common viviparous ancestor.<ref>{{Cite journal |last=Mao |first=Fangyuan |last2=Li |first2=Zhiyu |last3=Wang |first3=Zhili |last4=Zhang |first4=Chi |last5=Rich |first5=Thomas |last6=Vickers-Rich |first6=Patricia |last7=Meng |first7=Jin |date=2024-04-03 |title=Jurassic shuotheriids show earliest dental diversification of mammaliaforms |url=https://www.nature.com/articles/s41586-024-07258-7 |journal=Nature |language=en |doi=10.1038/s41586-024-07258-7 |issn=0028-0836|url-access=subscription }}</ref>

At least two lineages developed hypsodonty, in which tooth enamel extends beyond the gumline: lambdopsalid taeniolabidoideans<ref name=willbru>{{cite journal|last1=Williamson|first1=Thomas E.|last2=Brusatte|first2=Stephen L.|last3=Secord|first3=Ross|last4=Shelley|first4=Sarah|title=A new taeniolabidoid multituberculate (Mammalia) from the middle Puercan of the Nacimiento Formation, New Mexico, and a revision of taeniolabidoid systematics and phylogeny|journal=Zoological Journal of the Linnean Society|volume=177|pages=183–208|date=2015|doi=10.1111/zoj.12336|doi-access=free}}</ref> and sudamericid gondwanatheres.<ref>{{Cite web|url=https://books.google.com/books?id=JgKGv2aQxggC&q=gondwanatheria+grass&pg=PA32|title=Gondwanatheria}}{{dead link|date=September 2021}}</ref>

Studies published in 2018 demonstrated that multituberculates had relatively complex brains, some braincase regions even absent in therian mammals.<ref>{{cite journal |last1=Crompton |first1=A. W. |last2=Musinsky |first2=C. |last3=Rougier |first3=G. W. |last4=Bhullar |first4=B.-A. S. |last5=Miyamae |first5=J. A. |title=Origin of the Lateral Wall of the Mammalian Skull: Fossils, Monotremes and Therians Revisited |journal=Journal of Mammalian Evolution |date=September 2018 |volume=25 |issue=3 |pages=301–313 |doi=10.1007/s10914-017-9388-7 |s2cid=16072755 }}</ref>

==Evolution==

Multituberculates first appear in the fossil record during the Jurassic period, and then survived and even dominated for over one hundred million years, longer than any other order of mammaliforms, including placental mammals. The earliest known multituberculates are from the Middle Jurassic (Bathonian ~166-168 million years ago) of England and Russia, including ''Hahnotherium'' ''and Kermackodon'' from the Forest Marble Formation of England, and ''Tashtykia'' and ''Tagaria'' from the Itat Formation of Russia. These forms are only known from isolated teeth, which bear close similarity to those of euharamyidans, which they are suspected to be closely related to.<ref name="Averianov-2021">{{cite journal |last1=Averianov |first1=Alexander O. |last2=Martin |first2=Thomas |last3=Lopatin |first3=Alexey V. |last4=Schultz |first4=Julia A. |last5=Schellhorn |first5=Rico |last6=Krasnolutskii |first6=Sergei |last7=Skutschas |first7=Pavel |last8=Ivantsov |first8=Stepan |title=Multituberculate mammals from the Middle Jurassic of Western Siberia, Russia, and the origin of Multituberculata |journal=Papers in Palaeontology |date=May 2021 |volume=7 |issue=2 |pages=769–787 |doi=10.1002/spp2.1317 |s2cid=219067218 |issn=2056-2799 |url=https://zenodo.org/record/3877503 }}</ref> During the Late Jurassic and Early Cretaceous, basal multituberculates, collectively grouped into the paraphyletic "Plagiaulacida", were abundant and widespread across Laurasia (including Europe, Asia and North America). During the Aptian stage of the Early Cretaceous, the advanced subgroup Cimolodonta appeared in North America, characterised by a reduced number of lower premolars, with a blade-like lower fourth premolar. By the early Late Cretaceous (Cenomanian) Cimolodonta had replaced all other multituberculate lineages.<ref>{{Cite journal|last1=Weaver|first1=Lucas N.|last2=Wilson|first2=Gregory P.|last3=Krumenacker|first3=L. J.|last4=Mclaughlin|first4=Kayla|last5=Moore|first5=Jason R.|last6=Varricchio|first6=David J.|date=2019-03-04|title=New multituberculate mammals from the mid-Cretaceous (lower Cenomanian) Wayan Formation of southeastern Idaho and implications for the early evolution of Cimolodonta|url=https://www.tandfonline.com/doi/full/10.1080/02724634.2019.1604532|journal=Journal of Vertebrate Paleontology|language=en|volume=39|issue=2|article-number=e1604532|doi=10.1080/02724634.2019.1604532|bibcode=2019JVPal..39E4532W |s2cid=196655261 |issn=0272-4634|url-access=subscription}}</ref>

During the Late Cretaceous, multituberculates experienced an adaptive radiation, corresponding with a shift towards herbivory.<ref>{{Cite journal|last1=Wilson|first1=Gregory P.|last2=Evans|first2=Alistair R.|last3=Corfe|first3=Ian J.|last4=Smits|first4=Peter D.|last5=Fortelius|first5=Mikael|last6=Jernvall|first6=Jukka|date=March 2012|title=Adaptive radiation of multituberculate mammals before the extinction of dinosaurs|url=https://www.nature.com/articles/nature10880|journal=Nature|language=en|volume=483|issue=7390|pages=457–460|doi=10.1038/nature10880|pmid=22419156 |bibcode=2012Natur.483..457W |s2cid=4419772 |issn=1476-4687|url-access=subscription}}</ref> Multituberculates reached their peak diversity during the early Paleocene, shortly after the Cretaceous–Paleogene extinction event, but declined from the mid Paleocene onwards, likely due to competition with placental mammals such as rodents and ungulates. The group finally became extinct in the Late Eocene.<ref>{{Cite journal|last1=Adams|first1=Neil F.|last2=Rayfield|first2=Emily J.|last3=Cox|first3=Philip G.|last4=Cobb|first4=Samuel N.|last5=Corfe|first5=Ian J.|date=March 2019|title=Functional tests of the competitive exclusion hypothesis for multituberculate extinction|journal=Royal Society Open Science|language=en|volume=6|issue=3|article-number=181536|doi=10.1098/rsos.181536|doi-access=free|issn=2054-5703|pmc=6458384|pmid=31032010|bibcode=2019RSOS....681536A }}</ref><ref name="Brocklehurst et al 2021">{{cite journal|last1=Brocklehurst|first1=Neil|last2=Panciroli|first2=Elsa|last3=Benevento|first3=Gemma Louise|last4=Benson|first4=Roger B. J.|date=July 2021|title=Mammaliaform extinctions as a driver of the morphological radiation of Cenozoic mammals|journal=Current Biology|volume=31|issue=13|pages=2955–2963.e4|doi=10.1016/j.cub.2021.04.044|pmid=34004143|s2cid=234782605|url=https://ora.ox.ac.uk/objects/uuid:bda82407-db76-4c15-b061-ceb9ae271dd5 |doi-access=free}}</ref>

There are some isolated records of multituberculates from the Southern Hemisphere, including the cimolodontan ''Corriebaatar'' from the Early Cretaceous of Australia,<ref name="Rich-2022">{{Cite journal |last1=Rich |first1=Thomas |last2=Trusler |first2=Peter |last3=Kool |first3=Lesley |last4=White |first4=Matt A. |last5=Bevitt |first5=Joseph |last6=Morton |first6=Steven |last7=Vickers−Rich |first7=Patricia |date=2022 |title=Second specimen of Corriebaatar marywaltersae from the Lower Cretaceous of Australia confirms its multituberculate affinities |journal=Acta Palaeontologica Polonica |volume=67 |doi=10.4202/app.00924.2021 |s2cid=247905998 |issn=0567-7920|doi-access=free }}</ref> and fragmentary remains from the Late Cretaceous Maevarano Formation of Madagascar.<ref>{{Cite journal |last1=Krause |first1=David W. |last2=Hoffmann |first2=Simone |last3=Werning |first3=Sarah |date=December 2017 |title=First postcranial remains of Multituberculata (Allotheria, Mammalia) from Gondwana |journal=Cretaceous Research |language=en |volume=80 |pages=91–100 |doi=10.1016/j.cretres.2017.08.009|bibcode=2017CrRes..80...91K |doi-access=free }}</ref> The family Ferugliotheriidae from the Late Cretaceous of South America, traditionally considered gondwanatherians, may actually be cimolodontan multituberculates.<ref name="Rich-2022" />

During the Late Cretaceous and Paleocene the multituberculates radiated into a wide variety of morphotypes, including the squirrel-like arboreal ptilodonts. The peculiar shape of their last lower premolar is their most outstanding feature. These teeth were larger and more elongated than the other cheek-teeth and had an occlusive surface forming a serrated slicing blade. Though it can be assumed that this was used for crushing seeds and nuts, it is believed that most small multituberculates also supplemented their diet with insects, worms, and fruits.<ref name="Agusti-3" /> Tooth marks attributed to multituberculates are known on ''Champsosaurus'' fossils, indicating that at least some of these mammals were scavengers.<ref>{{cite journal | doi = 10.1111/j.1475-4983.2010.00957.x | volume=53 | title=Mammalian tooth marks on the bones of dinosaurs and other Late Cretaceous vertebrates | journal=Palaeontology | pages=703–709 | last1 = Longrich | first1 = Nicholas R. | last2 = Ryan | first2 = Michael J.| year=2010 | issue=4 | bibcode=2010Palgy..53..703L | doi-access = free }}</ref> A ptilodont that thrived in North America was ''Ptilodus''. Thanks to the well-preserved ''Ptilodus'' specimens found in the Bighorn Basin, Wyoming, we know that these multituberculates were able to abduct and adduct their big toes, and thus that their foot mobility was similar to that of modern squirrels, which descend trees head first.<ref name="Agusti-3" />

[[File:Catopsbaatar.jpg|thumb|left|Restoration of ''Catopsbaatar'']]

Another group of multituberculates, the taeniolabids, were heavier and more massively built, indicating that they lived a fully terrestrial life. The largest specimens weighed probably as much as {{convert|22|kg|abbr=on}}, making them comparable in size to large rodents like the modern beaver.<ref>Krause et al 2021</ref><ref>Wilson et al 2012</ref>

== Classification == Multituberculata is generally placed within Allotheria alongside Euharamiyida, a clade of mammals known from the Middle Jurassic to Early Cretaceous of Asia and possibly Europe that possess several morphological similarities with multituberculates.<ref name="Averianov-2021" /><ref name="Hoffmann-2020">{{Cite journal |last1=Hoffmann |first1=Simone |last2=Beck |first2=Robin M. D. |last3=Wible |first3=John R. |last4=Rougier |first4=Guillermo W. |last5=Krause |first5=David W. |date=2020-12-14 |title=Phylogenetic placement of Adalatherium hui (Mammalia, Gondwanatheria) from the Late Cretaceous of Madagascar: implications for allotherian relationships |url=https://www.tandfonline.com/doi/full/10.1080/02724634.2020.1801706 |journal=Journal of Vertebrate Paleontology |language=en |volume=40 |issue=sup1 |pages=213–234 |doi=10.1080/02724634.2020.1801706 |bibcode=2020JVPal..40S.213H |s2cid=230968231 |issn=0272-4634|url-access=subscription }}</ref>

Gondwanatheria is a monophyletic group of allotherians that was diverse in the Late Cretaceous of South America, India, Madagascar and possibly Africa and occurs onwards into the Paleogene of South America and Antarctica. Their placement within Allotheria is highly controversial, with some phylogenies recovering the group as deeply nested within multituberculates, while others recover them as a distinct branch of allotherians separate from multituberculates.<ref name="Hoffmann-2020" />thumb|Restoration of ''Taeniolabis taoensis'' In their 2001 study, Kielan-Jaworowska and Hurum found that most multituberculates could be referred to two suborders: "Plagiaulacida" and Cimolodonta. The exception is the genus ''Arginbaatar'', which shares characteristics with both groups.

"Plagiaulacida" is paraphyletic, representing the more primitive evolutionary grade. Its members are the more basal Multituberculata. Chronologically, they ranged from perhaps the Middle Jurassic until the mid-Cretaceous. This group is further subdivided into three informal groupings: the allodontid line, the paulchoffatiid line, and the plagiaulacid line.

Cimolodonta is, apparently, a natural (monophyletic) suborder. This includes the more derived Multituberculata, which have been identified from the lower Cretaceous to the Eocene. The superfamilies Djadochtatherioidea, Taeniolabidoidea, Ptilodontoidea are recognized, as is the Paracimexomys group. Additionally, there are the families Cimolomyidae, Boffiidae, Eucosmodontidae, Kogaionidae, Microcosmodontidae and the two genera ''Uzbekbaatar'' and ''Viridomys''. More precise placement of these types awaits further discoveries and analysis.<ref name="Dykes">Dykes ''Multituberculata (Cope 1884)''</ref>{{better source needed|date=April 2015|reason=Dykes' site is defunct}}

===Taxonomy=== {{collapse top|title=Subgroups |left=yes}} thumb|Multituberculate phylogenetic tree<ref name="Chimento et al 2015">{{cite journal |author1=Nicolás R. Chimento |author2=Federico L. Agnolin |author3=Fernando E. Novas |year=2015 |title=The bizarre 'metatherians' ''Groeberia'' and ''Patagonia'', late surviving members of gondwanatherian mammals |journal=Historical Biology: An International Journal of Paleobiology |volume=27 |issue=5 |pages=603–623 |doi=10.1080/08912963.2014.903945 |s2cid=216591096 |hdl=11336/85076 |hdl-access=free }}</ref> {{Main|List of multituberculate species}} Based on the combined works of Mikko's Phylogeny Archive<ref name="mikko">[http://www.helsinki.fi/~mhaaramo/ Mikko's Phylogeny Archive] {{cite web|last=Haaramo|first=Mikko|year=2007|title=''Mammaliaformes – mammals and near-mammals'' |url=http://www.helsinki.fi/~mhaaramo/metazoa/deuterostoma/chordata/synapsida/basal_mammalia/mammaliaformes_1.html |access-date= 30 December 2015}}</ref>{{better source needed|date=January 2026|reason=Not a scientific source, although itself based on scientific sources}} and Paleofile.com.{{citation needed|date=November 2020}}

Suborder †'''Plagiaulacida''' Simpson 1925 * Genus ?†''Argillomys'' Cifelli, Gordon & Lipka 2013 ** Species †''Argillomys marylandensis'' Cifelli, Gordon & Lipka 2013 * Genus ?†''Janumys'' Eaton & Cifelli 2001 ** Species †''Janumys erebos'' Eaton & Cifelli 2001 * Super family †'''Allodontoidea''' Marsh 1889 ** Genus †?''Glirodon'' Engelmann & Callison, 2001 *** Species †''G. grandis'' Engelmann & Callison, 2001 ** Family †'''Arginbaataridae''' Hahn & Hahn, 1983 *** Genus †''Arginbaatar'' Trofimov, 1980 **** Species †''A. dmitrievae'' Trofimov, 1980 ** Family †'''Zofiabaataridae''' Bakker, 1992 *** Genus †''Zofiabaatar'' Bakker & Carpenter, 1990 **** Species †''Z. pulcher'' Bakker & Carpenter, 1990 ** Family †'''Allodontidae''' Marsh, 1889 *** Genus †''Passumys'' Cifelli, Davis & Sames 2014 **** Species †''Passumys angelli'' Cifelli, Davis & Sames 2014 *** Genus †''Ctenacodon'' Marsh, 1879 **** Species †''C. serratus'' Marsh, 1879 **** Species †''C. nanus'' Marsh, 1881 **** Species †''C. laticeps'' (Marsh, 1881) [''Allodon laticeps'' Marsh 1881] **** Species †''C. scindens'' Simpson, 1928 *** Genus †''Psalodon'' Simpson, 1926 **** Species †''P. potens'' (Marsh, 1887) [''Ctenacodon potens'' Marsh 1887] **** Species †''P. fortis'' (Marsh, 1887) Simpson 1929 [''Allodon fortis'' Marsh 1887] **** Species †''P. marshi'' Simpson, 1929 * Super family †'''Paulchoffatioidea''' Hahn 1969 sensu Hahn & Hahn 2003 ** Genus ?†''Mojo'' Hahn, LePage & Wouters 1987 *** Species †''Mojo usuratus'' Hahn, LePage & Wouters 1987 ** Genus ?†''Rugosodon'' Yuan et al., 2013 *** Species †''Rugosodon eurasiaticus'' Yuan et al., 2013 ** Family †'''Pinheirodontidae''' Hahn & Hahn, 1999 *** Genus †''Bernardodon'' Hahn & Hahn, 1999 **** Species †''B. atlanticus'' Hahn & Hahn, 1999 **** Species †''B. sp.'' Hahn & Hahn, 1999 *** Genus †''Cantalera'' Badiola, Canudo & Cuenca-Bescos, 2008 **** Species †''Cantalera abadi'' Badiola, Canudo & Cuenca-Bescos, 2008 *** Genus †''Ecprepaulax'' Hahn & Hahn, 1999 **** Species †''E. anomala'' Hahn & Hahn, 1999 *** Genus †''Gerhardodon'' Kielan-Jaworowska & Ensom, 1992 **** Species †''G. purbeckensis'' Kielan-Jaworowska & Ensom, 1992 *** Genus †''Iberodon'' Hahn & Hahn, 1999 **** Species †''I. quadrituberculatus'' Hahn & Hahn, 1999 *** Genus †''Lavocatia'' Canudo & Cuenca-Bescós, 1996 **** Species †''L. alfambrensis'' Canudo & Cuenca-Bescós, 1996 *** Genus †''Pinheirodon'' Hahn & Hahn, 1999 **** Species †''P. pygmaeus'' Hahn & Hahn, 1999 **** Species †''P. vastus'' Hahn & Hahn, 1999 ** Family †'''Paulchoffatiidae''' Hahn, 1969 *** Genus ?†''Galveodon'' Hahn & Hahn, 1992 **** Species †''G. nannothus'' Hahn & Hahn, 1992 *** Genus ?†''Sunnyodon'' Kielan-Jaworowska & Ensom, 1992 **** Species †''S. notleyi'' Kielan-Jaworowska & Ensom, 1992 *** subfamily †Paulchoffatiinae Hahn, 1971 **** Genus †''Paulchoffatia'' Kühne, 1961 ***** Species †''P. delgador'' Kühne, 1961 **** Genus †''Pseudobolodon'' Hahn, 1977 ***** Species †''P. oreas'' Hahn, 1977 ***** Species †''P. krebsi'' Hahn & Hahn, 1994 **** Genus †''Henkelodon'' Hahn, 1987 ***** Species †''H. naias'' Hahn, 1987 **** Genus †''Guimarotodon'' Hahn, 1969 ***** Species †''G. leiriensis'' Hahn, 1969 **** Genus †''Meketibolodon'' (Hahn, 1978) Hahn, 1993 ***** Species †''M. robustus'' (Hahn, 1978) Hahn, 1993 [''Pseudobolodon robusutus'' Hahn 1978] **** Genus †''Plesiochoffatia'' Hahn & Hahn, 1999 [''Parachoffatia'' Hahn & Hahn 1998 non Mangold 1970] ***** Species †''P. thoas'' (Hahn & Hahn, 1998) Hahn & Hahn 1999 [''Parachoffatia thoa'' Hahn & Hahn 1998] ***** Species †''P. peparethos'' (Hahn & Hahn, 1998) Hahn & Hahn 1999 [''Parachoffatia peparethos'' Hahn & Hahn 1998] ***** Species †''P. staphylos'' (Hahn & Hahn, 1998) Hahn & Hahn 1999 [''Parachoffatia staphylos'' Hahn & Hahn 1998] **** Genus †''Xenachoffatia'' Hahn & Hahn, 1998 ***** Species †''X. oinopion'' Hahn & Hahn, 1998 **** Genus †''Bathmochoffatia'' Hahn & Hahn, 1998 ***** Species †''B. hapax'' Hahn & Hahn, 1998 **** Genus †''Kielanodon'' Hahn, 1987 ***** Species †''K. hopsoni'' Hahn, 1987 **** Genus †''Meketichoffatia'' Hahn, 1993 ***** Species †''M. krausei'' Hahn, 1993 **** Genus †''Renatodon'' Hahn, 2001 ***** Species †''Renatodon amalthea'' Hahn, 2001 *** Subfamily †Kuehneodontinae Hahn, 1971 **** Genus †''Kuehneodon'' Hahn, 1969 ***** Species †''K. dietrichi'' Hahn, 1969 ***** Species †''K. barcasensis'' Hahn & Hahn, 2001 ***** Species †''K. dryas'' Hahn, 1977 ***** Species †''K. guimarotensis'' Hahn, 1969 ***** Species †''K. hahni'' Antunes, 1988 ***** Species †''K. simpsoni'' Hahn, 1969 ***** Species †''K. uniradiculatus'' Hahn, 1978 {{collapse top|title='''Plagiaulacoidea''' |left=yes}} * Super family †'''Plagiaulacoidea''' Ameghino, 1894 ** Family †'''Plagiaulacidae''' Gill, 1872 sensu Kielan-Jaworowska & Hurum, 2001 [Bolodontidae Osborn 1887] *** Genus ?†''Morrisonodon'' Hahn & Hahn, 2004 **** Species †''Morrisonodon brentbaatar'' (Bakker, 1998) Hahn & Hahn, 2004 [''Ctenacodon brentbaatar'' Bakker, 1998] *** Genus †''Plagiaulax'' Falconer, 1857 **** Species †''P. becklesii'' Falconer, 1857 **** Species †''P. dawsoni'' Woodward, 1891 [''Plioprion dawsoni'' Woodward, 1891; ''Loxaulax dawsoni'' (Woodward, 1891) Sloan, 1979] *** Genus †''Bolodon'' Owen, 1871 [''Plioprion'' Cope, 1884] **** Species †''B. crassidens'' Owen, 1871 **** Species †''B. falconeri'' Owen, 1871 [''Pligiaulax falconeri'' Owen, 1871; ''Plioprion falconeri'' (Owen, 1871)] **** Species †''B. hydei'' Cifelli, Davis & Sames, 2014 **** Species †''B. minor'' Falconer, 1857 [''Pligiaulax minor'' Falconer, 1857; ''Plioprion minor'' (Falconer, 1857)] **** Species †''B. osborni'' Simpson, 1928 [''Plioprion osborni'' (Simpson, 1928); ''Ctenacodon osborni'' Simpson, 1928] **** Species ?†''B. elongatus'' Simpson, 1928 * Family †'''Eobaataridae''' Kielan-Jaworowska, Dashzeveg & Trofimov, 1987 ** Genus †''Eobaatar'' Kielan-Jaworowska, Dashzeveg & Trofimov, 1987 *** Species †''E. clemensi'' Sweetman, 2009 *** Species †''E. hispanicus'' Hahn & Hahn, 1992 *** Species †''E. magnus'' Kielan-Jaworowska, Dashzeveg & Trofimov, 1987 *** Species †''E. minor'' Kielan-Jaworowska, Dashzeveg & Trofimov, 1987 *** Species †''E. pajaronensis'' Hahn & Hahn, 2001 ** Genus †''Hakusanobaatar'' Kusuhashi et al., 2008 *** Species †''H. matsuoi'' Kusuhashi et al., 2008 ** Genus †''Heishanobaatar'' Kusuhashi et al., 2010 *** Species †''H. triangulus'' Kusuhashi et al., 2010 ** Genus †''Iberica'' Badiola et al., 2011 *** Species †''Iberica hahni'' Badiola et al., 2011 ** Genus †''Liaobaatar'' Kusuhashi et al., 2009 *** Species †''L. changi'' Kusuhashi et al., 2009 ** Genus †''Loxaulax'' Simpson, 1928 [''Parendotherium'' Crusafont Pairó & Adrover, 1966] *** Species †''L. valdensis'' (Woodward, 1911) Simpson, 1928[''Dipriodon valdensis'' Woodward, 1911] *** Species †''L. herreroi'' (Crusafont Pairó & Adrover, 1966) [''Parendotherium herreroi'' Crusafont Pairó & Adrover 1966] ** Genus †''Monobaatar'' Kielan-Jaworowska, Dashzeveg & Trofimov, 1987 *** Species †''M. mimicus'' Kielan-Jaworowska, Dashzeveg & Trofimov, 1987 ** Genus †''Sinobaatar'' Hu & Wang, 2002 *** Species †''S. lingyuanensis'' Hu & Wang, 2002 *** Species †''S. xiei'' Kusuhashi et al., 2009 *** Species †''S. fuxinensis'' Kusuhashi et al., 2009 ** Genus †''Tedoribaatar'' Kusuhashi et al., 2008 *** Species †''T. reini'' Kusuhashi et al., 2008 ** Genus †''Teutonodon'' Martin et al., 2016 *** Species †''Teutonodon langenbergensis'' Martin et al. 2016 * Family †'''Albionbaataridae''' Kielan-Jaworowska & Ensom, 1994 ** Genus †''Albionbaatar'' Kielan-Jaworowska & Ensom, 1994 *** Species †''A. denisae'' Kielan-Jaworowska & Ensom, 1994 ** Genus †''Kielanobaatar'' Kusuhashi et al., 2010 *** Species †''K. badaohaoensis'' ''Kusuhashi et al.'', 2010 ** Genus †''Proalbionbaatar'' Hahn & Hahn, 1998 *** Species †''P. plagiocyrtus'' Hahn & Hahn, 1998 * Suborder †'''Gondwanatheria''' McKenna 1971 [Gondwanatheroidea Krause & Bonaparte 1993] ** Family †'''Groeberiidae''' Patterson, 1952 *** Genus †''Groeberia'' Patterson 1952 **** Species †''G. minoprioi'' Ryan Patterson, 1952 **** Species †''G. pattersoni'' G. G. Simpson, 1970 *** Genus †''Klohnia'' Flynn & Wyss 1999 **** Species †''K. charrieri'' Flynn & Wyss 1999 **** Species †''K. major'' Goin et al., 2010 *** Genus ?†''Epiklohnia'' Goin et al., 2010 **** Species †''Epiklohnia verticalis'' Goin et al., 2010 *** Genus ?†''Praedens'' Goin et al., 2010 **** Species †''Praedens aberrans'' Goin et al., 2010 ** Family †'''Ferugliotheriidae''' Bonaparte, 1986 *** Genus †''Ferugliotherium'' Bonaparte, 1986a [''Vucetichia'' Bonaparte, 1990] **** †''Ferugliotherium windhauseni'' Bonaparte, 1986a [''Vucetichia gracilis'' Bonaparte, 1990] *** Genus †''Trapalcotherium'' Rougier et al., 2008 **** †''Trapalcotherium matuastensis'' Rougier et al., 2008 ** Family †'''Sudamericidae''' Scillato-Yané & Pascual, 1984 [Gondwanatheridae Bonaparte, 1986; Patagonidae Pascual & Carlini, 1987] *** Genus †''Greniodon'' Goin et al., 2012 **** †''Greniodon sylvanicus'' Goin et al., 2012 *** Genus †''Vintana'' Krause et al., 2014 **** †''Vintana sertichi'' Krause et al., 2014 *** Genus †''Dakshina'' Wilson, Das Sarama & Anantharaman, 2007 **** †''Dakshina jederi'' Wilson, Das Sarama & Anantharaman, 2007 *** Genus †''Gondwanatherium'' Bonaparte, 1986 **** †''Gondwanatherium patagonicum'' Bonaparte, 1986 *** Genus †''Sudamerica'' Scillato-Yané & Pascual, 1984 **** †''Sudamerica ameghinoi'' Scillato-Yané & Pascual, 1984 *** Genus †''Lavanify'' Krause et al., 1997 **** †''Lavanify miolaka'' Krause et al., 1997 *** Genus †''Bharattherium'' Prasad et al., 2007 **** †''Bharattherium bonapartei'' Prasad et al.,, 2007 *** Genus †''Patagonia'' Pascual & Carlini' 1987 **** †''Patagonia peregrina'' Pascual & Carlini' 1987 {{collapse bottom}} {{collapse top|title='''Cimolodonta''' |left=yes}} * Suborder †'''Cimolodonta''' McKenna, 1975 ** Genus ?†''Allocodon'' non Marsh, 1881 *** Species †''A. fortis'' Marsh, 1889 *** Species †''A. lentus'' Marsh, 1892 [''Cimolomys lentus''] *** Species †''A. pumilis'' Marsh, 1892 [''Cimolomys pumilus''] *** Species †''A. rarus'' Marsh, 1889 ** Genus ?†''Ameribaatar'' Eaton & Cifelli, 2001 *** Species †''A. zofiae'' Eaton & Cifelli, 2001 ** Genus ?†''Bubodens'' Wilson, 1987 *** Species †''Bubodens magnus'' Wilson, 1987 ** Genus ?†''Clemensodon'' Krause, 1992 *** Species †''Clemensodon megaloba'' Krause, 1992 [''Kimbetohia cambi'', in partim] ** Genus ?†''Fractinus'' Higgins 2003 *** Species †''Fractinus palmorum'' Higgins, 2003 ** Genus ?†''Uzbekbaatar'' Kielan-Jaworowska & Nesov, 1992 *** Species †''Uzbekbaatar kizylkumensis'' Kielan-Jaworowska & Nesov, 1992 ** Genus ?†''Viridomys'' Fox 1971 *** Species †''Viridomys orbatus'' Fox 1971 ** Family †'''Corriebaataridae''' Rich et al., 2009 *** Genus ?†''Corriebaatar'' Rich et al., 2009 **** Species †''Corriebaatar marywaltersae'' Rich et al., 2009 ** ''Paracimexomys'' group *** Genus ''Paracimexomys'' Archibald, 1982 **** Species? †''P. crossi'' Cifelli, 1997 **** Species? †''P. dacicus'' Grigorescu & Hahn, 1989 **** Species? †''P. oardaensis'' (Codrea et al., 2014) [''Barbatodon oardaensis'' Codrea et al., 2014] **** Species †''P. magnus'' (Sahni, 1972) Archibald, 1982 [''Cimexomys magnus'' Sahni, 1972] **** Species †''P. magister'' (Fox, 1971) Archibald, 1982 [''Cimexomys magister'' Fox, 1971] **** Species †''P. perplexus'' Eaton & Cifelli, 2001 **** Species †''P. robisoni'' Eaton & Nelson, 1991 **** Species †''P. priscus'' (Lillegraven, 1969) Archibald, 1982 [''Cimexomys priscus'' Lillegraven, 1969; genotype Paracimexomys sensu Eaton & Cifelli, 2001] **** Species †''P. propriscus'' Hunter, Heinrich & Weishampel 2010 *** Genus ''Cimexomys'' Sloan & Van Valen, 1965 **** Species †''C. antiquus'' Fox, 1971 **** Species †''C. gregoryi'' Eaton, 1993 **** Species †''C. judithae'' Sahni, 1972 [''Paracimexomys judithae'' (Sahni, 1972) Archibald, 1982] **** Species †''C. arapahoensis'' Middleton & Dewar, 2004 **** Species †''C. minor'' Sloan & Van Valen, 1965 **** Species? †''C. gratus'' (Jepson, 1930) Lofgren, 1995 [''Cimexomys hausoi'' Archibald, 1983; ''Eucosmodon gratus'' Jepson, 1930; ''Mesodma ambigua''? Jepson, 1940; ''Stygimus gratus'' Jepson, 1930] *** Genus †''Bryceomys'' Eaton, 1995 **** Species †''B. fumosus'' Eaton, 1995 **** Species †''B. hadrosus'' Eaton, 1995 **** Species †''B. intermedius'' Eaton & Cifelli, 2001 *** Genus †''Cedaromys'' Eaton & Cifelli, 2001 **** Species †''C. bestia'' (Eaton & Nelson, 1991) Eaton & Cifelli, 2001 [''Paracimexomys bestia'' Eaton & Nelson, 1991] **** Species †''C. hutchisoni'' Eaton 2002 **** Species †''C. minimus'' Eaton 2009 **** Species †''C. parvus'' Eaton & Cifelli, 2001 *** Genus †''Dakotamys'' Eaton, 1995 **** Species? †''D. sp.'' Eaton, 1995 **** Species †''D. malcolmi'' Eaton, 1995 **** Species †''D. shakespeari'' Eaton 2013 ** Family †'''Boffidae''' Hahn & Hahn, 1983 sensu Kielan-Jaworowska & Hurum 2001 *** Genus †''Boffius'' Vianey-Liaud, 1979 **** Species †''Boffius splendidus'' Vianey-Liaud, 1979 [Boffiidae Hahn & Hahn, 1983 sensu Kielan-Jaworowska & Hurum, 2001] ** Family †'''Cimolomyidae''' Marsh, 1889 sensu Kielan-Jaworowska & Hurum, 2001 *** Genus †''Paressodon'' Wilson, Dechense & Anderson, 2010 **** Species †''Paressodon nelsoni'' Wilson, Dechense & Anderson, 2010 *** Genus †''Cimolomys'' Marsh, 1889 [?''Allacodon'' Marsh, 1889; ''Selenacodon'' Marsh, 1889] **** Species †''C. clarki'' Sahni, 1972 **** Species †''C. gracilis'' Marsh, 1889 [''Cimolomys digona'' Marsh, 1889; ''Meniscoessus brevis''; ''Ptilodus gracilis'' Osborn, 1893 non Gidley 1909; ''Selenacodon brevis'' Marsh, 1889] **** Species †''C. trochuus'' Lillegraven, 1969 **** Species †''C. milliensis'' Eaton, 1993a **** Species ?†''C. bellus'' Marsh, 1889 *** Genus ?†''Essonodon'' Simpson, 1927 **** Species †''E. browni'' Simpson, 1927 [cimolodontidae? Kielan-Jaworowska & Hurum 2001] *** Genus ?†''Buginbaatar'' Kielan-Jaworowska & Sochava, 1969 **** Species †''Buginbaatar transaltaiensis'' Kielan-Jaworowska & Sochava, 1969 *** Genus ?†''Meniscoessus'' Cope, 1882 [''Dipriodon'' Marsh, 1889; ''Tripriodon'' Marsh, 1889 ''nomen dubium''; ''Triprotodon'' Chure & McIntosh, 1989 ''nomen dubium''; ''Selenacodon'' Marsh, 1889, ''Halodon'' Marsh, 1889, ''Oracodon'' Marsh, 1889] **** Species †''M. caperatus'' Marsh, 1889 **** Species †''M. collomensis'' Lillegraven, 1987 **** Species †''M. conquistus'' Cope 1882 **** Species †''M. ferox'' Fox, 1971a **** Species †''M. intermedius'' Fox, 1976b **** Species †''M. major'' (Russell, 1936) [''Cimolomys major'' Russell 1937] **** Species †''M. robustus'' (Marsh, 1889) [''Dipriodon robustus'' Marsh 1889; ''Dipriodon lacunatus'' Marsh, 1889; ''Tripriodon coelatus'' Marsh, 1889; ''Meniscoessus coelatus'' Marsh, 1889; ''Selenacodon fragilis'' Marsh, 1889; ''Meniscoessus fragilis'' Marsh, 1889; ''Halodon sculptus'' (Marsh, 1889); ''Cimolomys sculptus'' Marsh, 1889; ''Meniscoessus sculptus'' Marsh, 1889; ''Oracodon anceps'' Marsh, 1889; ''Oracodon conulus'' Marsh, 1892; ''Meniscoessus borealis'' Simpson, 1927c; ''Meniscoessus greeni'' Wilson, 1987] **** Species †''M. seminoensis'' Eberle & Lillegraven, 1998a ** Family †'''Kogaionidae''' Rãdulescu & Samson, 1996 *** Genus †''Kogaionon'' Rãdulescu & Samson, 1996 **** Species †''K. ungureanui'' Rãdulescu & Samson, 1996 *** Genus †''Hainina'' Vianey-Liaud, 1979 **** Species †''H. belgica'' Vianey-Liaud, 1979 **** Species †''H. godfriauxi'' Vianey-Liaud, 1979 **** Species †''H. pyrenaica'' Peláez-Campomanes, López-Martínez, Álvarez-Sierra & Daams, 2000 **** Species †''H. vianeyae'' Peláez-Campomanes, López-Martínez, Álvarez-Sierra & Daams, 2000 *** Genus †''Barbatodon'' Rãdulescu & Samson, 1986 **** Species †''B. transylvanicum'' Rãdulescu & Samson, 1986 ** Family †'''Eucosmodontidae''' Jepsen, 1940 sensu Kielan-Jaworowska & Hurum, 2001 [Eucosmodontidae: Eucosmodontinae Jepsen, 1940 sensu McKenna & Bell, 1997] *** Genus †''Eucosmodon'' Matthew & Granger, 1921 **** Species †''E. primus'' Granger & Simpson, 1929 **** Species †''E. americanus'' Cope, 1885 **** Species †''E. molestus'' Cope, 1869 [''Neoplagiaulax molestus'' Cope, 1869] *** Genus †''Stygimys'' Sloan & Van Valen, 1965 **** Species †''S. camptorhiza'' Johnston & Fox, 1984 **** Species †''S. cupressus'' Fox, 1981 **** Species †''S. kuszmauli'' [''Eucosmodon kuszmauli''] **** Species †''S. jepseni'' Simpson, 1935 **** Species †''S. teilhardi'' Granger & Simpson, 1929 ** Family †'''Microcosmodontidae''' Holtzman & Wolberg, 1977 [Eucosmodontidae: Microcosmodontinae Holtzman & Wolberg, 1977 sensu McKenna & Bell, 1997] *** Genus †''Pentacosmodon''Jepsen, 1940 **** Species †''P. pronus'' Jepsen, 1940 [Djadochtatheroid? (Kielan-Jaworowska & Hurum, 2001)] *** Genus †''Acheronodon'' Archibald, 1982 **** Species †''A. garbani'' Archibald, 1982 *** Genus †''Microcosmodon'' Jepsen, 1930 **** Species †''M. conus'' Jepsen, 1930 **** Species †''M. rosei'' Krause, 1980 **** Species †''M. arcuatus'' Johnston & Fox, 1984 **** Species †''M. woodi'' Holtzman & Wolberg, 1977 [Eucosmodontine?] **** Species †''M. harleyi'' Weil, 1998 ** Superfamily †Ptilodontoidea Cope, 1887 sensu McKenna & Bell, 1997 e Kielan-Jaworowska & Hurum, 2001 *** Family †'''Cimolodontidae''' Marsh, 1889 sensu Kielan-Jaworowska & Hurum, 2001 **** Genus †''Liotomus'' Lemoine, 1882 [''Neoctenacodon'' Lemoine 1891] ***** Species? †''L. marshi'' (Lemoine, 1882) Cope, 1884 [''Neoctenacodon marshi'' Lemoine, 1882; ''Neoplagiaulax marshi'' (Lemoine 1882); ''Plagiaulax marshi'' (Lemoine 1882)] [Eucosmodontidae? McKenna & Bell, 1997] **** Genus †''Yubaatar'' Xu et al., 2015 ***** Species †''Yubaatar zhongyuanensis'' Xu et al., 2015 **** Genus †''Anconodon'' Jepsen, 1940 ***** Species? †''A. lewisi'' (Simpson 1935) Sloan, 1987 ***** Species †''A. gibleyi'' (Simpson, 1935) [''Ptilodus gidleyi'' Simpson, 1935] ***** Species †''A. cochranensis'' (Russell, 1929) [''Liotomus russelli'' (Simpson, 1935); ''Anconodon russelli'' (Simpson, 1935) Sloan, 1987; ''Ectopodon cochranensis'' (Russell, 1967)] **** Genus †''Cimolodon'' Marsh, 1889 [''Nanomys'' Marsh, 1889, ''Nanomyops'' Marsh, 1892] ***** Species †''C. agilis'' Marsh, 1889 ***** Species †''C. foxi'' Eaton, 2002 ***** Species †''C. gracilis'' Marsh, 1889 ***** Species †''C. electus'' Fox, 1971 ***** Species †''C. nitidus'' Marsh, 1889 [''Allacodon rarus'' Marsh, 1892 sensu Clemens, 1964a; ''Nanomys minutus'' Marsh, 1889; ''Nanomyops minutus'' (Marsh, 1889) Marsh, 1892; ''Halodon serratus'' Marsh, 1889; ''Ptilodus serratus'' (Marsh, 1889) Gidley 1909] ***** Species †''C. parvus'' Marsh, 1889 ***** Species †''C. peregrinus'' Donohue, Wilson & Breithaupt, 2013 ***** Species †''C. similis'' Fox, 1971 ***** Species †''C. wardi'' Eaton, 2006 *** Family ''Incertae sedis'' **** Genus ''Neoliotomus'' Jepsen, 1930 ***** Species †''N. conventus'' Jepsen, 1930 ***** Species †''N. ultimus'' (Granger & Simpson, 1928) *** Family †'''Neoplagiaulacidae''' Ameghino, 1890 [Ptilodontidae: Neoplagiaulacinae Ameghino, 1890 sensu McKenna & Bell, 1997] **** Genus †''Mesodma'' Jepsen, 1940 ***** Species? †''M. hensleighi'' Lillegraven, 1969 ***** Species? †''M. senecta'' Fox, 1971 ***** Species †''M. ambigua'' Jepsen, 1940 ***** Species? †''M. pygmaea'' Sloan, 1987 ***** Species †''M. formosa'' (Marsh, 1889) [Halodon formosus Marsh, 1889] ***** Species †''M. primaeva'' (Lambe, 1902) ***** Species †''M. thompsoni'' Clemens, 1964 **** Genus ''Ectypodus'' Matthew & Cranger, 1921 [Charlesmooria Kühne, 1969 ] ***** Species †''E. aphronorus'' Sloan, 1981 ***** Species? †''E. childei'' Kühne, 1969 ***** Species? †''E. elaphus'' Scott, 2005 ***** Species? †''E. lovei'' (Sloan, 1966) Krishtlaka & Black, 1975 ***** Species †''E. musculus'' Matthew & Granger, 1921 ***** Species †''E. powelli'' Jepsen, 1940 ***** Species? †''E. simpsoni'' Jepsen, 1930 ***** Species †''E. szalayi'' Sloan, 1981 ***** Species †''E. tardus'' Jepsen, 1930 **** Genus †''Mimetodon'' Jepsen, 1940 ***** Species †''M. krausei'' Sloan, 1981 ***** Species †''M. nanophus'' Holtzman, 1978 [''Neoplagiaulax nanophus'' Holtzman, 1978] ***** Species †''M. siberlingi''(Simpson, 1935) Schiebout, 1974 ***** Species †''M. churchilli'' Jepsen, 1940 **** Genus †''Neoplagiaulax'' Lemoine, 1882 ***** Species †''N. annae'' Vianey-Liaud, 1986 ***** Species? †''N. burgessi'' Archibald, 1982 ***** Species †''N. cimolodontoides'' Scott, 2005 ***** Species †''N. copei'' Lemoine, 1885 ***** Species †''N. donaldorum'' Scott & Krause, 2006 ***** Species †''N. eocaenus'' Lemoine, 1880 ***** Species †''N. grangeri'' Simpson, 1935 ***** Species †''N. hazeni'' Jepsen, 1940 ***** Species †''N. hunteri'' Krishtalka, 1973 ***** Species †''N. jepi'' Sloan, 1987 ***** Species †''N. kremnus'' Johnston & Fox, 1984 ***** Species †''N. macintyrei'' Slaon, 1981 ***** Species †''N. macrotomeus'' Wilson, 1956 ***** Species †''N. mckennai'' Sloan, 1987 ***** Species †''N. nelsoni'' Sloan, 1987 ***** Species †''N. nicolai'' Vianey-Liaud, 1986 ***** Species †''N. paskapooensis'' Scott, 2005 ***** Species? †''N. serrator'' Scott, 2005 ***** Species †''N. sylvani'' Vianey-Liaud, 1986 **** Genus †''Parectypodus'' Jepsen, 1930 ***** Species †''P. armstrongi'' Johnston & Fox, 1984 ***** Species? †''P. corystes'' Scott, 2003 ***** Species? †''P. foxi'' Storer, 1991 ***** Species †''P. laytoni'' Jepsen, 1940 ***** Species †''P. lunatus'' Krause, 1982 [''P. childei'' Kühne, 1969] ***** Species †''P. simpsoni'' Jepsen, 1940 ***** Species †''P. sinclairi'' Simpson, 1935 ***** Species †''P. sloani'' Schiebout, 1974 ***** Species †''P. trovessartianus'' Cope, 1882 [''P. trouessarti''; ''Ptilodus''; ''Mimetodon''; ''Neoplagiaulax''] ***** Species †''P. sylviae'' Rigsby, 1980 [Ectypodus sylviae Rigby, 1980] ***** Species? †''P. vanvaleni'' Sloan, 1981 **** Genus †''Cernaysia'' Vianey-Liaud, 1986 ***** Species †''C. manueli'' Vianey-Liaud, 1986 ***** Species †''C. davidi'' Vianey-Liaud, 1986 **** Genus †''Krauseia'' Vianey-Liaud, 1986 ***** Species †''K. clemensi'' Sloan, 1981 [''Parectypodus clemensi'' Sloan, 1981] **** Genus †''Xyronomys''Rigby, 1980 ***** Species †''X. swainae'' Rigby, 1980 [Xironomys (sic); ?Eucosmodontidae] **** Genus †''Xanclomys'' Rigby, 1980 ***** Species †''X. mcgrewi''Rigby, 1980 **** Genus †''Mesodmops'' Tong & Wang, 1994 ***** Species †''M. dawsonae'' Tong & Wang, 1994 *** Family †'''Ptilodontidae''' Cope, 1887 [Ptilodontidae: Ptilodontinae Cope, 1887 sensu McKenna & Bell, 1997] **** Genus †''Kimbetohia'' Simpson, 1936 ***** Species †''K. cambi'' [Granger, Gregory & Colbert in Matthew, 1937, or Simpson, 1936] ***** Species †K. sp. cf. ''K. cambi'' **** Genus †''Ptilodus'' Cope, 1881 [Chirox Cope, 1884] ***** Species? †''P. fractus'' ***** Species †''P. kummae'' Krause, 1977 ***** Species †''P. gnomus'' Scott, Fox & Youzwyshyn, 2002 [cf. ''Ectypodus hazeni'' (Jepsen, 1940) Gazin, 1956] ***** Species †''P. mediaevus'' Cope, 1881 [''Ptilodus plicatus'' (Cope, 1884); ''Chirox plicatus'' Cope, 1884 ''P. ferronensis'' Gazin, 1941] ***** Species †''P. montanus'' Douglass, 1908 [''P. gracilis'' Gidley, 1909; ''P. admiralis'' Hay, 1930] ***** Species †''P. tsosiensis'' Sloan, 1981 ***** Species †''P. wyomingensis'' Jepsen, 1940 **** Genus †''Baiotomeus'' Krause, 1987 ***** Species †''B. douglassi'' Simpson, 1935 [''Ptilodus''; ''Mimetodon''; ''Neoplagiaulax''] ***** Species †''B. lamberti'' Krause, 1987 ***** Species †''B. russelli'' Scott, Fox & Youzwyshyn, 2002 ***** Species †''B. rhothonion'' Scott, 2003 **** Genus †''Prochetodon'' Jepsen, 1940 ***** Species †''P. cavus'' Jespen, 1940 ***** Species †''P. foxi'' Krause, 1987 ***** Species †''P. taxus'' Krause, 1987 ***** Species? †''P. speirsae'' Scott, 2004 ** Superfamily †'''Taeniolabidoidea''' Granger & Simpson, 1929 sensu Kielan-Jaworowska & Hurum, 2001 *** Genus †''Prionessus'' Matthew & Granger, 1925 **** Species †''P. lucifer'' Matthew & Granger, 1925 *** Family †'''Lambdopsalidae''' **** Genus †''Lambdopsalis'' Chow & Qi, 1978 ***** Species †''L. bulla'' Chow & Qi, 1978 **** Genus †''Sphenopsalis'' Matthew, Granger & Simpson, 1928 ***** Species †''S. nobilis'' Matthew, Granger & Simpson, 1928 *** Family †'''Taeniolabididae''' Granger & Simpson, 1929 **** Genus †''Taeniolabis'' Cope, 1882 ***** Species †''T. lamberti'' Simmons, 1987 ***** Species †''T. taoensis'' Cope, 1882 **** Genus †''Kimbetopsalis'' ***** Species †''K. simmonsae'' ** Superfamily †'''Djadochtatherioidea''' Kielan-Jaworowska & Hurum, 1997 sensu Kielan-Jaworowska & Hurum, 2001[Djadochtatheria Kielan-Jaworowska & Hurum, 1997] *** Genus? †''Bulganbaatar'' Kielan-Jaworowska, 1974 **** Species? †''B. nemegtbaataroides'' Kielan-Jaworowska, 1974 *** Genus †''Nemegtbaatar'' Kielan-Jaworowska, 1974 **** Species? †''N. gobiensis'' Kielan-Jaworowska, 1974 *** Family †'''Chulsanbaataridae''' Kielan-Jaworowska, 1974 **** Genus †''Chulsanbaatar'' Kielan-Jaworowska, 1974 ***** Species †''C. vulgaris'' Kielan-Jaworowska, 1974 *** Family †'''Sloanbaataridae''' Kielan-Jaworowska, 1974 **** Genus †''Kamptobaatar'' Kielan-Jaworowska, 1970 ***** Species? †''K. kuczynskii'' Kielan-Jaworowska, 1970 **** Genus †''Nessovbaatar'' Kielan-Jaworowska & Hurum, 1997 ***** Species †''N. multicostatus'' Kielan-Jaworowska & Hurum, 1997 **** Genus †''Sloanbaatar'' Kielan-Jaworowska, 1974 ***** Species †''S. mirabilis'' Kielan-Jaworowska, 1974 [Sloanbaatarinae] *** Family †'''Djadochtatheriidae''' Kielan-Jaworowska $ Hurum, 1997 **** Genus †''Djadochtatherium'' Simpson, 1925 ***** Species †''D. matthewi'' Simpson, 1925[''Catopsalis matthewi'' Simpson, 1925] **** Genus †''Catopsbaatar'' Kielan-Jaworowska, 1974 ***** Species †''C. catopsaloides'' (Kielan-Jaworowska, 1974) Kielan-Jaworowska, 1994 [''Djadochtatherium catopsaloides'' Kielan-Jaworowska, 1974] **** Genus †''Tombaatar'' Kielan-Jaworowska, 1974 ***** Species †''T. sabuli'' Rougier, Novacek & Dashzeveg, 1997 **** Genus †''Kryptobaatar'' Kielan-Jaworowska, 1970 [''Gobibaatar'' Kielan-Jaworowska, 1970, ''Tugrigbaatar'' Kielan-Jaworowska & Dashzeveg, 1978] ***** Species †''K. saichanensis'' Kielan-Jaworowska & Dashzeveg, 1978 [''Tugrigbaatar saichaenensis'' Kielan-Jaworowska & Dashzeveg, 1978??] ***** Species †''K. dashzevegi'' Kielan-Jaworowska, 1970 ***** Species †''K. mandahuensis'' Smith, Guo & Sun, 2001 ***** Species †''K. gobiensis'' Kielan-Jaworowska, 1970 [''Gobibaatar parvus'' Kielan-Jaworowska, 1970 ] {{collapse bottom}} {{collapse bottom}}

===Phylogeny=== After Chimento et al. 2015:<ref name="Chimento et al 2015"/>

{{clade |style= |label1='''Multituberculata''' |1={{clade |1=Paulchoffatiidae |2={{clade |1=Plagiaulacidae |2={{clade |1=Eobaataridae |2={{clade |label1=Gondwanatheria |1={{clade |1=Ferugliotheriidae |2={{clade |1=Groeberiidae |2=Sudamericidae}}}} |label2=Cimolodonta |2={{clade |1=Cimolodontidae |2={{clade |1=Ptilodontoidea |2={{clade |1={{clade |1=''Cimexomys'' |2=Cimolomyidae}} |2={{clade |1=''Boffius'' |2=''Buginbaatar'' |3=Eucosmodontidae |4=Microcosmodontidae |label5=Djadochtatherioidea |5={{clade |1=''Bulganbaatar'' |2={{clade |1={{clade |1=''Chulsanbaatar'' |2=Sloanbaataridae}} |2={{clade |1=''Nemegtbaatar'' |2=Djadochtatheriidae}}}}}} |6={{clade |1=Kogaionidae |label2=Taeniolabidoidea |2={{clade |1=''Yubaatar'' |2={{clade |1=''Bubodens'' |2={{clade |1=''Valenopsalis'' |2={{clade |1=Lambdopsalidae |2=Taeniolabididae}}}}}}}}}}}}}}}}}}}}}}}}}}}}Cladogram after Carvalho et al. 2025:<ref>{{Cite journal |last=Carvalho |first=Victor F. |last2=Camilo |first2=Bruno |last3=Araújo |first3=Ricardo |last4=Castro |first4=Lígia |last5=Kullberg |first5=José C. |last6=Desmet |first6=Hilde G. B. |last7=Nerinckx |first7=Ignace |last8=Leite |first8=Marco |last9=Reis |first9=Diego |date=March 2025 |title=Cambelodon torreensis, a new pinheirodontid multituberculate from the Upper Jurassic of western Portugal |url=https://onlinelibrary.wiley.com/doi/10.1002/spp2.70012 |journal=Papers in Palaeontology |language=en |volume=11 |issue=2 |doi=10.1002/spp2.70012 |issn=2056-2799|url-access=subscription }}</ref>{{clade |label1='''Multituberculata''' |1={{clade |1={{clade |1=Pinheirodontidae |2=Paulchoffatiidae }} |2={{clade |1=''Glirodon'' |2={{clade |1=''Ctenacodon'' |2={{clade |1=''Zofiabaatar'' |2={{clade |1=''Bolodon'' |2={{clade |1=''Plagiaulax'' |2={{clade |1=Eobaataridae |2={{clade |1=''Arginbaatar'' |2=Cimolodonta }}}}}}}}}}}}}}}}}}

==Paleoecology==

===Behaviour=== Multituberculates are some of the earliest mammals to display complex social behaviours. One species, ''Filikomys,'' from the Late Cretaceous of North America, engaged in multi-generational group nesting and burrowing.<ref>{{cite journal |last1=Weaver |first1=Lucas N. |last2=Varricchio |first2=David J. |last3=Sargis |first3=Eric J. |last4=Chen |first4=Meng |last5=Freimuth |first5=William J. |last6=Wilson Mantilla |first6=Gregory P. |title=Early mammalian social behaviour revealed by multituberculates from a dinosaur nesting site |journal=Nature Ecology & Evolution |date=2 November 2020 |volume=5 |issue=1 |pages=32–37 |doi=10.1038/s41559-020-01325-8 |pmid=33139921 |s2cid=226241443 }}</ref>

===Extinction===

The extinction of multituberculates has been a topic of controversy for several decades.<ref name="Wood 2010">{{Cite thesis |last=Wood |first=D. Joseph |title=The Extinction of the Multituberculates Outside North America: a Global Approach to Testing the Competition Model |type=M.S. |year=2010 |publisher=The Ohio State University |url=https://etd.ohiolink.edu/!etd.send_file?accession=osu1275595604&disposition=inline |access-date=2015-04-03 |archive-date=2015-04-08 |archive-url=https://web.archive.org/web/20150408104907/https://etd.ohiolink.edu/!etd.send_file?accession=osu1275595604&disposition=inline }}</ref> After at least 88 million years of dominance over most mammalian assemblies, multituberculates reached the peak of their diversity in the early Palaeocene, before gradually declining across the final stages of the epoch and the Eocene, finally disappearing in the early Oligocene.<ref name="Ostrander 1984">{{cite journal |last1=Ostrander |first1=Gregg |title=The Early Oligocene (Chadronian) Raben Ranch Local Fauna, Northwest Nebraska: Multituberculata; with Comments on the Extinction of the Allotheria |journal=Transactions of the Nebraska Academy of Sciences and Affiliated Societies |date=1 January 1984 |url=https://digitalcommons.unl.edu/tnas/239/ }}</ref>

The last multituberculate species, ''Ectypodus childei'', went extinct near the end of the Eocene in North America. It is unclear why this particular species persisted for so long when all of its counterparts succumbed to replacement by rodents.<ref>{{Cite thesis |title=The Extinction of the Multituberculates Outside North America: a Global Approach to Testing the Competition Model |url=https://etd.ohiolink.edu/apexprod/rws_olink/r/1501/10?clear=10&p10_accession_num=osu1275595604 |publisher=The Ohio State University |date=2010 |language=en |first=D. Joseph |last=Wood |access-date=2023-05-19 |archive-date=2023-05-19 |archive-url=https://web.archive.org/web/20230519082943/https://etd.ohiolink.edu/apexprod/rws_olink/r/1501/10?clear=10&p10_accession_num=osu1275595604 }}</ref>{{Rp|page=43}}

Traditionally, the extinction of multituberculates has been linked to the rise of rodents (and, to a lesser degree, earlier placental competitors like hyopsodonts and Plesiadapiformes), which supposedly competitively excluded multituberculates from most mammalian faunas.<ref name="Krause 1986">{{cite book |doi=10.2113/gsrocky.24.special_paper_3.95 |chapter=Competitive exclusion and taxonomic displacement in the fossil record |title=Vertebrates, Phylogeny, and Philosophy |year=1986 |last1=Krause |first1=David W. |pages=95–117 |isbn=978-0-941570-02-2 |chapter-url=https://archive.org/details/vertebratesphylo0000unse/page/95 }}</ref> Adams et al. (2019) argued in favor of this hypothesis as rodents have a higher bite force than multituberculates, which would have given them access to harder, drier seeds which were becoming more abundant and had a greater range of food compared to multituberculates. The authors also argued rodents had was longer gestation periods and larger neonates which gave them a competitive advantage over multituberculates. In addition, they believed the diversity of new predators such as owls, creodonts, and carnivorans, also played a role in their extinction.<ref>{{Cite journal |last=Adams |first=Neil F. |last2=Rayfield |first2=Emily J. |last3=Cox |first3=Philip G. |last4=Cobb |first4=Samuel N. |last5=Corfe |first5=Ian J. |date=2019 |title=Functional tests of the competitive exclusion hypothesis for multituberculate extinction |url=https://royalsocietypublishing.org/doi/10.1098/rsos.181536#d1e1774 |journal=Royal Society Open Science |volume=6 |issue=3 |doi=10.1098/rsos.181536 |doi-access=free|pmc=6458384 }}</ref>

However, the idea that multituberculates were competitively replaced by rodents and other placentals has been criticised by several authors. For one thing, it relies on the assumption that these mammals are "inferior" to more derived placentals, and ignores the fact that rodents and multituberculates had co-existed for at least 15 million years. According to some researchers, multituberculate "decline" is shaped by sharp extinction events, most notably after the Tiffanian, where a sudden drop in diversity occurs. Finally, the youngest known multituberculates do not exemplify patterns of competitive exclusion; the Oligocene ''Ectypodus'' is a rather generalistic species, rather than a specialist. This suggests that multituberculates simply could not cope with climatic and vegetation changes, as well as the rise of new predatory eutherians, such as miacids. However, rodents probably still played a role in their decline.<ref name="Ostrander 1984"/>

More recent studies show a mixed effect. Multituberculate faunas in North America and Europe do indeed decline in correlation to the introduction of rodents in these areas. However, Asian multituberculate faunas co-existed with rodents with minimal extinction events, implying that competition was not the main cause for the extinction of Asiatic multituberculates. As a whole, it seems that Asian multituberculates, unlike North American and European species, never recovered from the KT event, which allowed the evolution and propagation of rodents in the first place.<ref name="Wood 2010"/> A recent study seems to indeed indicate that eutherians recovered more quickly from the KT event than multituberculates.<ref>{{cite journal |last1=Pires |first1=Mathias M. |last2=Rankin |first2=Brian D. |last3=Silvestro |first3=Daniele |last4=Quental |first4=Tiago B. |year=2018 |title=Diversification dynamics of mammalian clades during the K–Pg mass extinction |journal=Biology Letters |volume=14 |issue=9 |page=2058 |doi=10.1098/rsbl.2018.0458 |pmc=6170748 |pmid=30258031}}</ref> Conversely, another study has shown that placental radiation did not start significantly until after the decline of multituberculates.<ref name="Brocklehurst et al 2021" />

However, competitive replacement among North American species has been called into question by Benjamin John Burger in his 2025 study. He suggests the extinction of multituberculates in North America was correlated to the decline of boreal forests that were dominated by dawn redwoods and Chinese swamp cypress. The analysis suggested that multituberculates avoided pine and spruce-dominated forests despite having similar geographic distributions to those trees. However, Burger argues competitive replacements by seed-eating passerine birds such as songbirds, and several mammalian groups such as paromomyids, may have played a role in the extinction of multituberculates, although this requires more testing.<ref>{{Cite journal |last=Burger |first=Benjamin John |date=2025 |title=Comparative spatial paleoecology: assessing niche competition between Eocene North American multituberculates and rodents regarding forest resources to elucidate the cause of multituberculate extinction |url=https://www.cambridge.org/core/journals/paleobiology/article/comparative-spatial-paleoecology-assessing-niche-competition-between-eocene-north-american-multituberculates-and-rodents-regarding-forest-resources-to-elucidate-the-cause-of-multituberculate-extinction/B1D9E93C24C909E16DB263F77468289E |journal=Paleobiology |pages=1–16 |doi=10.1017/pab.2025.10048 |doi-access=free}}</ref>

==References== {{Reflist}}

==Sources== {{Commons category}} {{Wikispecies|Multituberculata}} *{{cite book |title = Mammoths, Sabertooths, and Hominids: 65 Millions Years of Mammalian Evolution in Europe |first1 = Jordi|last1=Agustí|first2=Mauricio|last2 = Antón |publisher = Columbia University Press|location=New York|year = 2002 |isbn = 978-0-231-11640-4 }} *{{cite web|url=http://home.arcor.de/ktdykes/multis.htm |title=Multituberculata (Cope 1884) |first=Trevor |last=Dykes |archive-url=https://web.archive.org/web/20091228041258/http://home.arcor.de/ktdykes/multis.htm |archive-date=December 28, 2009 }} *{{cite journal |last1 = Kielan-Jaworowska|first1 = Zofia|last2=Hurum|first2 = Jørn H. |title = Phylogeny and Systematics of multituberculate mammals |journal = Palaeontology|year=2001|issue=3|volume=44|pages=389–429|doi=10.1111/1475-4983.00185 | bibcode=2001Palgy..44..389K | s2cid=83592270 | url=http://doc.rero.ch/record/14775/files/PAL_E1903.pdf }}

Category:Multituberculata Category:Prehistoric tetrapod orders Category:Mammal orders Category:Oligocene extinctions Category:Kimmeridgian first appearances Category:Taxa named by Edward Drinker Cope Category:Tertiary extinctions of vertebrate taxa